The present invention relates generally to bottom-discharge semi-trailers and, more particularly, to semi-trailers with integrated unloading and discharge conveyors.
A common piece of equipment used in the course of transporting agricultural commodities and many other bulk materials is a xe2x80x9cbulk commodityxe2x80x9d semi-tractor trailer. These trailers may be approximately 42 feet in length with side walls between 66 inches and 84 inches in height. They typically have a rectangular shaped open top and have sloped internal surfaces that direct the material contained within to smaller openings in the bottom of the trailer which are used to discharge the material. Such trailers, as illustrated in FIG. 1, are generally referred to as bottom-discharge or xe2x80x9chopperxe2x80x9d trailers and are typically unloaded by opening a door that covers the bottom of the opening at the bottom of the trailer. The material then falls freely into an auger or a pit at an elevator.
Although some trailers have been built which have an attached device to move the material away from the bottom of the trailer, such trailers are not common yet common. FIG. 2 illustrates one type of trailer 200 which includes a bottom conveyor 202 which receives material discharged from a discharge opening 204 and transports it to the back 206 of the trailer. The bottom conveyor is mounted horizontally under the trailer body. The material is then deposited onto an auger, onto another conveyor or into a pit and moved into storage.
FIG. 3 illustrates another trailer 300 which includes both a bottom conveyor 302 and a discharge conveyor 304. The bottom conveyor 302 received material from the discharge opening, transports it rear-ward and deposits it onto the discharge conveyor 304. The discharge conveyor 304 is rigidly mounted to the trailer 300 and transports the material at an angle upward beyond the back end of the trailer 300. The end 306 of the discharge conveyor 304 is approximately 11 feet above the ground and 13 feet behind the rear of the trailer 300. When the trailer is in transit, the angled discharge conveyor is typically pivoted to a lower position such that the end is approximately 8 feet above the ground and extends 15 feet behind the trailer.
Vehicles which travel the Federal Interstate System or the Federal Highway System are subject safety related legislation established by the Federal government. These are for the most part documented in the Federal Motor Vehicle Safety Standards (FMVSS) which publishes laws and regulations with which the manufacturers of motor vehicles must comply and similar Federal Motor Carrier Safety Regulations (FMCSR) with which all operators of motor vehicles must also comply. Of particular relevance are the regulations directed towards reducing the number of serious accidents in which a car, particularly a small car, in is in a xe2x80x9crear underridexe2x80x9d incident. In such an accident, the car impacts the rear of a tractor-trailer and slides underneath the trailer, being crushed in the process. Regulations, such as those published in Title 49 of the Code of Federal Regulations, Sections 571.223 and 224, have been enacted which require certain trailers to have rear impact guards attached to the chassis to prevent a car from sliding under the vehicle. Among other requirements, a rear impact guard must be mounted so that its rear surface is no more than a prescribed distance (currently 305 millimeters) forward of the vertical plane of the rear extremity of the vehicle. In the event that the rear-most axle of the trailer is permanently fixed and located within the prescribed distance (305 mm) of the rear extremity of the vehicle (a xe2x80x9cwheels backxe2x80x9d configuration), the rear axle may serve as the rear impact guard.
It will be apparent that the discharge conveyor of the trailer of FIG. 3 does not comply with the Regulations because the conveyor extends the rear extremity of the trailer to such an extent that the distance between the rear impact guard, even in a wheels back configuration, and the rear extremity is greater than the prescribed distance. Thus, if a car impacted the rear of such a trailer, the discharge conveyor would strike and penetrate the passenger compartment before the car could be stopped by the rear impact guard. Even though the discharge conveyor may be removable, a substantial amount of time and effort is necessary for its removal. Consequently, as a practical matter, an operator is not likely to remove the discharge conveyor before moving the trailer on roads and highways and therefore the trailer will not be in compliance with the Regulations and will pose a significant danger to the traveling public.
FIG. 4 illustrates another discharge conveyor 404 (in the form of a chute) for a trailer 400. The conveyor 404 is hinged, allowing the discharge end 406 to fold back and down against the trailer 400 when not in use. Although the conveyor 404 does not extend behind the trailer 400 as does the conveyor 304 in FIG. 3, it is still not in compliance with the Regulations and therefore poses a significant danger to the traveling public.
Consequently, there remains a need for a self-unloading, bottom-discharge trailer which can be transported on roads and highways without violating highway safety regulations and presenting a danger to motorists.
The present invention provides a discharge conveyor extension for a self-unloading, bottom-discharge trailer. In a working position, the discharge conveyor transports material from a trailer container upwards beyond the rear of the trailer for depositing into storage. In a transport position, a rear section of the discharge conveyor is folded downwards into a substantially vertical position, resting against the rear of the trailer frame and not substantially protruding beyond the back of the trailer.
In one embodiment, a self-unloading, bottom-discharge trailer is provided with a discharge conveyor. In a working position, the discharge conveyor transports material from a trailer container upwards beyond the rear of the trailer for depositing into storage. In a transport position, a rear section of the discharge conveyor is folded downwards into a substantially vertical position, resting against the rear of the trailer frame and not substantially protruding beyond the back of the trailer. The frame may include a recess sized to accommodate the rear section such that the rear section is substantially flush with the rear of the frame. Consequently, the trailer may remain in compliance with highway safety regulations.